The Armalite Rifle (AR) platform has been the standard battle rifle platform of the United States for the past fifty years. Introduced in the 1960s as a replacement for the M-14 rifle, M-16s were deployed in Vietnam as the military's new standard battle rifle. The M-16 was originally known as the AR-15, the designation originating from the Armalite Company that produced the first M-16s.
In the intervening years, the AR platform evolved to more sophisticated configurations and capabilities. One major innovation was the introduction of the Picatinny rail system adopted as a standardized mounting system that allows accessories from multiple vendors to be mounted on the battle rifle and interchangeable from one weapon to another.
The Picatinny rail, alternatively known as the U.S. MIL-STD-1913 rail, NATO STANAG 2324 rail, or simply “Tactical Rail,” is a bracket used on firearms in order to provide a standardized mounting platform. The Picatinny rail is a dovetail or T-shaped mount with transverse grooves that prevent the mounting accessory from moving back and forth due to recoil. The rail comprises a series of ridges with a T-shaped cross-section interspersed with flat “spacing slots.” Accessories are mounted either by sliding them on from one end to the other by means of a mount that is clamped to the rail with bolts, thumbscrews or levers, or onto the slots between raised sections.
With the advent of the Picatinny rail system, manufacturers began producing various accessories to aid soldiers in the field with a wide array of products ranging from multiple telescopic sights, range-finding devices, red-dot aiming devices, laser aiming devices, rail-mounted flashlights, alternate sights, and bi-pods, all of which represent the majority of categories of accessories available for mounting on the Picatinny rails. Vertical foregrips and other accessories mounted at the six o'clock position on shoulder-fired weapons have become known in military, law enforcement and civilian arenas.
A vertical foregrip is designed to attach to a firearm for the forward hand (or “offhand”). Such vertical foregrips aid in the maneuverability of the firearm, since the natural angle of a person's outstretched hand is more oriented to grasping objects at a vertical angle, rather than a horizontal one perpendicular to the body. Prior art foregrips attachable to rifles provide some levels of utilization but are less functional in design. Most foregrips of this type are constructed whereby the interior of the foregrip is a hollow cavity for storing “small parts.” Other uses comprise installing batteries inside the foregrip cavity to power Picatinny rail-mounted flashlights, or where the foregrip and flashlight are an integral unit and the batteries again are contained within the foregrip cavity. Some prior art grips provide the option of allowing the foregrip to be positioned at various angles.